This invention relates generally to wire spooling equipment, and more particularly to devices of the type adapted to facilitate the unreeling of wire from a spool.
Applicant's U.S. Pat. No. 3,425,647 shows a pay-off cap assembly for use with wire-filled spools, comprising a stationary circular tension brush and a freely rotatable wheel having a wheel flange extending over the end of the spool, for engagement with and rotation by a strand of wire being unreeled. The combination of a stationary brush and rotatable wheel has been found to be a very effective means for preventing excessive looseness and kinking of wire, especially under widely varying conditions of wire size and take-off speed.
Such cap assemblies are typically employed with spools several feet in diameter, weighing hundreds of pounds. In the past, the rotatable wheel portion of the cap assembly has been fabricated in steel, often as a single piece. The installation and removal of such cap assemblies involving heavy wheels was frequently difficult for one person to manage. Also, where heavy wheels were employed, their inertia at rest was sometimes too great to be overcome by the strand during initiation of pay out.
Under high speed conditions, the angular momentum developed by a massive steel wheel caused problems if there was a sudden reduction in pay-out speed, in that the wheel continued to rotate at a high speed for a short interval, causing additional unwinding of wire from the spool and leading to excessive looseness in the strand.
Furthermore, there existed a possibility that the wheel would rotate in synchronism with the unreeling strand, especially under constant speeds. This often resulted in a point contact between the wheel and the strand, with the latter also undergoing simultaneous twisting movement as wire was paid off. This had the effect of gouging the wheel at a single point, causing excessive wear, and later on resulting in a tendency for the strand to catch on the wheel each time it passed the worn or gouged point. Such damage at a limited area on the wheel eventually necessitated its replacement, resulting in needless expense and substantial down time.